Conventionally, a navigation system for use in a subject vehicle provides navigation instructions for an occupant in the subject vehicle by optimally calculating a navigation route toward a destination. Japanese Patent Document JP-A-2001-74486 discloses the navigation system that provides the navigation instruction by using an audio sound or by displaying a map. The navigation system finishes provision of standard navigation instructions, which are generally provided by using a voice in an audible manner, when the subject vehicle is located in the proximity of the destination, and the navigation system displays a detailed map of the destination including the destination and a current position of the subject vehicle.
However, the occupant, or a driver of the subject vehicle, has to repeatedly gaze the detailed map displayed on the navigation system to grasp the navigation instructions in the map after the provision of the standard navigation instructions has finished. Therefore, the driver of the subject vehicle has inconvenience in terms of receiving instructions from the navigation system.
Further, the navigation system occasionally provides the navigation route that is too complicated to be recognized at a glance of the instructions on the map, or to be understood by using the audio sound, or by using other instruction means.
Furthermore, the navigation instruction provided by the system is occasionally vague for the driver when the destination, e.g., a private house or the like, has no particular feature in appearance. Therefore, the driver of the vehicle cannot proceed with certainty toward the destination by merely obeying the navigation instructions provided by the navigation system.